Posted
by
ScuttleMonkey
on Monday July 10, 2006 @02:02PM
from the mr-griffin's-wild-ride dept.

Jivecat writes "All those extra cameras NASA has added to the Space Shuttle to watch for debris impacts have yielded what may be the coolest Shuttle launch footage ever. The forward-facing view from the right-hand SRB shows, at about the 2:58 mark, booster separation and Discovery zooming away. Other views are available at the main mission site."

Nice to see our government is looking out for the interests of all and protecting the freedom of all to access govt. publications by putting these in a proprietary format like Windows Media Video.

The camera supplier [eclipticenterprises.com] has a history of offering these amazing videos in MPEG format. Lets hope the new Discovery videos will be added to the last. The image of the orbiter/ET accelerating from the spent boosters is some of the most spectacular aerospace footage I have ever seen.

Something like 4m 30s of freefall (3:00-7:30) on that video. Very neat. Can someone with greater knowledge than I explain how the camera survived re-entry, or is there no re-entry at that altitude yet?

The SRB's never technically 'leave' the atmosphere so they can't re-enter. They are going pretty fast but not Mach 25 like the shuttle and station are doing on orbit. Maybe a few (2-4) Mach. Actually the shuttle goes quite slow while the SRB's are on because the atmosphere is so dense at low altitudes (the SRB's are only on for just over 2 minutes) because dynamic pressure builds up quickly ( a linear function of air density and a square of velocity ) so you keep your velocity at a fair clip until the atmosphere thins and then speed up. Long story short the SRB's aren't going that fast, and the cameras are in a good housing. The cam itself is made by these guys [eclipticenterprises.com]

No total re-entry at that altitude (otheriwse the entire booster would fry). Also, if you watch the entire footage you can see the parachute deployed. In addition I imagine NASA has some protective covering over the camera, to help a bit.

About 125 seconds after launch and at an altitude of about 150,000 feet, the SRB's burn out and are jettisoned from the ET. The jettison command originates from the Orbiter, and jettison occurs when the forward and aft attach points between the SRB's and ET are blown by explosive charges.

1:30-1:40 Mach transition (breaking the sound barrier - watch the nose)2:39 a rather visible bit of debris flies right past the camera2:58 separation from the orbiter/tank stack3:59 as the booster tumbles, you can briefly spot the shuttle as a bright dot5:18 you can see the smoke plume thru the upper atmosphere7:13 some debris goes past the booster camera7:17 you can see a shroud (parachute) line falling7:25 you can very briefly see a chute7:30 water entry7:40 the chute falls into the water8:00 as the booster floats, the chutes and shroud lines are clearly visible around the booster

Yes, it has been resized, cropped and compressed. Someone else posted a link to an MPEG file from NASA that was twice the resolution. Apparently it was from an analog NTSC source. It was full of interlacing artifacts, and it had black bars on both sides. Whoever released the WMV apparently just discarded one set of fields and halved the horizontal resolution instead of deinterlacing. They also cropped to remove the black bars and compressed it to a pretty low bitrate.

The tiles are modular. each with its own little barcode. The heat of re-entry is quite murderous to the surface of these tiles, and as they heat up the outer surface will oxidize and not look as glossy. Ever see the heat shield on an Apollo capsule? Looks very similar. Tiles in high stress/wear areas are more likely to detach from the orbiter, and their shiny black replacements can be seen in an up close view. The reasoning goes, if the tile is still good, if a bit cloudy, why replace it? It's an unnecessary expense to the taxpayer, and painting the tiles would add weight, cost, and have the paint burn away on re-entry.

I'm sorry but you'll just have to live with an unattractive but working heat shield.